Method for manufacturing semiconductor device

ABSTRACT

To improve the assemblability of a semiconductor device. 
     When a memory chip is mounted over a logic chip, a recognition range including a recognition mark formed at a back surface of the logic chip is imaged and a shape of the recognition range is recognized, alignment of a plurality of bumps of the logic chip and a plurality of projection electrodes of the above-described memory chip is performed based on a result of the recognition, and the above-described memory chip is mounted over the logic chip. At this time, the shape of the recognition range is different from any portion of an array shape of the bumps, as a result, the recognition mark in the shape of the recognition range can be reliably recognized, and alignment of the bumps of the logic chip and the projection electrodes of the above-described memory chip is performed with high accuracy.

CROSS-REFERENCE TO RELATED APPLICATION

The disclosure of Japanese Patent Application No. 2013-061088 filed onMar. 22, 2013 including the specification, drawings and abstract isincorporated herein by reference in its entirety.

BACKGROUND

The present invention relates to a manufacturing technology of asemiconductor device, and for example, to a technology effective inapplying to assembly of a semiconductor device having a semiconductorchip in which through electrodes have been formed.

For example, in Japanese Patent Laid-Open No. 2009-260373 (PatentDocument 1), there is disclosed a structure in which an alignment markis formed on a surface where a pad of a semiconductor chip has beenformed, and in which the alignment mark is used as a test-dedicated padwhich a probe and the like touch.

In addition, for example, in Japanese Patent Laid-Open No. 2005-175263(Patent Document 2), there is disclosed a technology in which alignmentmarks that are formed in the same step as a step of forming throughelectrodes and that have the same structure as each other are formed ona substrate, and in which alignment of a semiconductor chip to bestacked and the substrate is performed using the alignment marks.

In addition, for example, in Japanese Patent Laid-Open No. 2011-49318(Patent Document 3), there is disclosed a structure in which a pluralityof circuit regions is formed on an upper surface of a wafer, and inwhich an alignment mark is provided inside the respective circuitregions, and furthermore, it is described in this Patent Document 3 thattips of through electrodes formed on the wafer can be used as thealignment marks.

In addition, for example, it is disclosed in Japanese Patent Laid-OpenNo. 2008-153499 (Patent Document 4) that elements, constituting asemiconductor circuit, such as a transistor and a resistor, and wiringsthat should be coupled to the elements are sequentially formed on asemiconductor wafer on the basis of alignment marks, and thatthrough-holes are formed in the semiconductor wafer, and electrodes andthrough electrodes are formed.

SUMMARY

In a flow of a technology of reduction in size and high-density mountingof a semiconductor device (semiconductor package), currently,development of three-dimensional mounting technologies to achieve an SIP(System In Package) through the use of a three-dimensional structure hasbeen performed vigorously. Among the three-dimensional mountingtechnologies, particularly, the TSV (Through Silicon Via (siliconthrough electrode)) technology is a technology effective in reduction insize while stacking a number of chips, in which through-holes are boredin chips in a wafer state, a conductive material is buried in thethrough-holes for the formation of through electrodes, and in whichstacked chips are electrically coupled to one another via the throughelectrodes.

As one example of a semiconductor device using this TSV technology,there can be exemplified the semiconductor device in which there hasbeen performed flip-chip mounting of a first semiconductor chip (forexample, a logic chip) provided with through electrodes over a wiringsubstrate (package substrate), and in which there has been furthermounted (stacked) a second semiconductor chip (for example, a memorychip) provided with projection electrodes over a back surface of thefirst semiconductor chip. Electrode pads corresponding to the throughelectrodes are provided on the back surface of the first semiconductorchip, and the second semiconductor chip is electrically coupled to thefirst semiconductor chip through the above-mentioned projectionelectrodes, electrode pads, and through electrodes.

Such semiconductor device is assembled in the following procedures inmany cases.

1) An alignment mark formed on the wiring substrate is recognized by arecognition unit of a chip mounting machine.

2) The first semiconductor chip is mounted over the wiring substratebased on a recognition result of 1).

3) The alignment mark formed on the wiring substrate is recognized againby the recognition unit of the chip mounting machine.

4) The second semiconductor chip is mounted over the first semiconductorchip based on a recognition result of 3).

However, the inventor of the present application has found out that,when the alignment mark formed on the wiring substrate is used in commonin the above-described 1) and 3) steps as described above, positiondeviation (an mounting error or variation in mounting accuracy) of thefirst semiconductor chip with respect to the wiring substrate is addedto position deviation of the second semiconductor chip with respect tothe first semiconductor chip. That is, in the above-described 3) and 4)steps in which the alignment mark formed on the wiring substrate isrecognized, and in which the second semiconductor chip is mounted overthe first semiconductor chip. Accuracy of positions of the secondsemiconductor chip and the wiring substrate can be absolutely ensured,but accuracy of positions of the second semiconductor chip and the firstsemiconductor chip cannot be ensured. In addition to that, in recentyears, an adjacent pitch between a plurality of through electrodesformed at the first semiconductor chip is becoming narrower, forexample, approximately 50 μm, and an adjacent pitch of a plurality ofelectrode pads corresponding to the respective through electrodes isbecoming substantially the same. Therefore, when even slight positiondeviation occurs between the electrode pad of the first semiconductorchip and the projection electrode of the second semiconductor chip,stable coupling of the first semiconductor chip and the secondsemiconductor chip (stable coupling of the electrode pads and theprojection electrodes) cannot be secured.

Consequently, the inventor of the present application has examined thatthe alignment mark used in the above-described 3) step is provided overthe back surface of the first semiconductor chip in order to enhance(stabilize) alignment accuracy of the first semiconductor chip and thesecond semiconductor chip. However, the inventor of the presentapplication has found out a further problem that a shape of thealignment mark may approximate to an array shape of the plurality ofelectrode pads in some cases, which causes false recognition at the timeof recognition.

An object of an embodiment disclosed in the present application is toprovide a technology to be able to enhance assemblability of asemiconductor device.

The other problems and the new feature will become clear from thedescription of the present specification and the accompanying drawings.

A method for manufacturing a semiconductor device of one embodiment hasa step of mounting a second semiconductor chip over a firstsemiconductor chip, in which a plurality of electrode pads and arecognition mark are arranged over a main surface of the firstsemiconductor chip, and in which when the above-described secondsemiconductor chip is mounted, a recognition range including theabove-described recognition mark of the first semiconductor chip isimaged and a shape of the above-described recognition range isrecognized. Furthermore, alignment of the electrode pads of the firstsemiconductor chip and a plurality of projection electrodes of thesecond semiconductor chip is performed on the basis of a result of theabove-described recognition, and the second semiconductor chip ismounted over the first semiconductor chip. In that case, a shape of theabove-described recognition range is different from any portion of anarray shape of the above-described electrode pads.

According to the above-described one embodiment, assemblability of thesemiconductor device can be enhanced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating one example of a structureof a semiconductor device of an embodiment;

FIG. 2 shows partial cross-sectional views each of which illustrates oneexample of a structure of the semiconductor device of FIG. 1 after fromelement formation to wiring formation of assembly thereof;

FIG. 3 is a partial cross-sectional view illustrating one example of astructure of the semiconductor device of FIG. 1 after copper post bumpformation of the assembly thereof;

FIG. 4 shows partial cross-sectional views each of which illustrates oneexample of a structure of the semiconductor device of FIG. 1 after fromwafer support attachment to back surface polishing of the assemblythereof;

FIG. 5 is a partial cross-sectional view illustrating one example of astructure of the semiconductor device of FIG. 1 after back surface bumpformation in the assembly thereof;

FIG. 6 shows partial cross-sectional views each of which illustrates oneexample of a structure of the semiconductor device of FIG. 1 after fromtape application to carrier removal of the assembly thereof;

FIG. 7 is a partial cross-sectional view showing one example of astructure of the semiconductor device of FIG. 1 after dicing of theassembly thereof;

FIG. 8 is a partial cross-sectional view illustrating one example of astructure of the semiconductor device of FIG. 1 after flip-chip mountingof a lower-stage chip of the assembly thereof;

FIG. 9 is a partial cross-sectional view illustrating one example of astructure of the semiconductor device of FIG. 1 at the time of alignmentof the assembly thereof;

FIG. 10 is a partial cross-sectional view illustrating one example of astructure of the semiconductor device of FIG. 1 after flip-chip mountingof an upper-stage chip of the assembly thereof;

FIG. 11 is a conceptual diagram illustrating one example of a structureof a prober to which comparative examination has been made;

FIG. 12 shows a plan view and an enlarged plan view illustrating astructure of a front surface side of a wafer mounted in the prober ofFIG. 11;

FIG. 13 is a plan view illustrating a structure of aback surface side ofthe wafer mounted in the prober of FIG. 11;

FIG. 14 shows a plan view and a partial enlarged plan view illustratinga structure of an A portion of FIG. 13;

FIG. 15 is a conceptual diagram illustrating an alignment method towhich comparative examination has been made;

FIG. 16 shows a plan view and an enlarged partial plan view illustratinga recognition range recognized at the time of alignment shown in FIG.15;

FIG. 17 is a conceptual diagram illustrating one example of a state atthe time of alignment in a flip-chip step of the assembly of thesemiconductor device of FIG. 1;

FIG. 18 is a conceptual diagram illustrating one example of a structureof the semiconductor device of FIG. 1 after flip-chip mounting in theflip-chip step of the assembly thereof;

FIG. 19 is a cross-sectional view illustrating one example of astructure at the time of the alignment of FIG. 17;

FIG. 20 is a cross-sectional view illustrating one example of astructure after the flip-chip mounting shown in FIG. 18;

FIG. 21 is a plan view illustrating a structure of a front surface sideof a wafer used in the present embodiment;

FIG. 22 shows a plan view and a partial enlarged plan view illustratinga structure of an A portion of FIG. 21;

FIG. 23 shows a plan view of a semiconductor chip to which comparativeexamination has been made and partial enlarged plan views of patterns;

FIG. 24 is a block diagram illustrating one example of a structure of achip mounting machine used in the flip-chip step of the assembly of thesemiconductor device of FIG. 1;

FIG. 25 is a block diagram illustrating one example of a structure of aprober apparatus used in an inspection step of the assembly of thesemiconductor device of FIG. 1;

FIG. 26 is a partial cross-sectional view illustrating one example of aholding state of the wafer at the time of inspection in the proberapparatus of FIG. 25;

FIG. 27 shows cross-sectional views illustrating one example of arecognition mark formation step in a semiconductor chip incorporated inthe semiconductor device of FIG. 1;

FIG. 28 shows cross-sectional views illustrating one example of therecognition mark formation step in the semiconductor chip incorporatedin the semiconductor device of FIG. 1;

FIG. 29 shows cross-sectional views illustrating a first modification ofthe recognition mark formation step in the semiconductor chipincorporated in the semiconductor device of FIG. 1;

FIG. 30 is a conceptual diagram illustrating one example of pitches anda size of the patterns by through electrodes of FIG. 22;

FIG. 31 is a plan view illustrating one example of a structure of a backsurface side of a logic chip incorporated in the semiconductor device ofFIG. 1;

FIG. 32 shows a plan view and an enlarged partial plan view illustratingshapes of a recognition range of a second modification;

FIG. 33 shows a plan view and an enlarged partial plan view illustratingshapes of a recognition range of a third modification;

FIG. 34 shows a plan view and an enlarged partial plan view illustratingshapes of a recognition range of a fourth modification;

FIG. 35 shows a plan view and an enlarged partial plan view illustratingshapes of a recognition range of a fifth modification;

FIG. 36 shows a plan view and an enlarged partial plan view illustratingshapes of a recognition range of a sixth modification;

FIG. 37 shows a plan view and an enlarged partial plan view illustratingshapes of a recognition range of a seventh modification;

FIG. 38 is an enlarged plan view illustrating a shape of a recognitionrange of an eighth modification;

FIG. 39 is an enlarged plan view illustrating a shape of a recognitionrange of a ninth modification;

FIG. 40 is an enlarged plan view illustrating a shape of a recognitionrange of a tenth modification;

FIG. 41 is a cross-sectional view illustrating a structure of asemiconductor device of an eleventh modification of the embodiment;

FIG. 42 is an enlarged partial cross-sectional view illustrating astructure of a semiconductor device of a twelfth modification of theembodiment;

FIG. 43 is a cross-sectional view illustrating a structure asemiconductor device of a thirteenth modification of the embodiment; and

FIG. 44 is a cross-sectional view illustrating a structure of asemiconductor device of a fourteenth modification of the embodiment.

DETAILED DESCRIPTION

In the following embodiments, explanation of the same or similar portionis not repeated as a principle except for the case where it is necessaryin particular.

Furthermore, the following embodiments will be explained, divided intoplural sections or embodiments, if necessary for convenience. Except forthe case where it shows clearly in particular, they are not mutuallyunrelated and one has relationships such as a modification, details, andsupplementary explanation of some or entire of another.

In addition, in the following embodiments, when referring to the numberof elements or the like (including the number, a numeric value, anamount, a range, and the like) they may be not restricted to thespecific number but may be greater or smaller than the specific number,except for such cases where they are clearly specified in particular andwhere they are clearly restricted to a specific number theoretically.

Furthermore, in the following embodiments, it is needless to say that anelement (including an element step and the like) is not necessarilyindispensable, except for such cases where it is clearly specified inparticular and where it is considered to be clearly indispensable from atheoretical point of view.

In addition, in the following embodiments, it is needless to say thatwhen “comprising A”, “containing A”, “having A”, and “including A” aredescribed in regard to an element or the like, the other elements arenot eliminated except for such a case where it is clearly specified inparticular that only the element is included. Similarly, in thefollowing embodiments, when shape, position relationship, and the likeof an element or the like are referred to, what resembles or is similarto the shape substantially shall be included, except for the case whereit is clearly specified in particular and where it is considered to beclearly not right from a theoretical point of view. This statement alsoapplies to the numeric value and range described above.

Hereinafter, an embodiment will be explained in detail based ondrawings. It should be noted that in all the drawings for explaining theembodiment, the same symbol is attached to a member having the samefunction, and the repeated explanation thereof is omitted. In addition,in order to make a drawing intelligible, hatching may be attached evenif it is a plan view.

EMBODIMENT

FIG. 1 is a cross-sectional view illustrating one example of a structureof a semiconductor device of an embodiment.

The semiconductor device of the present embodiment is, as shown in FIG.1, a semiconductor package in which a plurality of semiconductor chipshas been stacked over a package substrate (wiring substrate) 3 on whicha wiring has been formed, and in the present embodiment, as one exampleof the above-described semiconductor package, there will be taken up andexplained a BGA (Ball Grid Array) 6 in which a plurality of ballelectrodes 9 serving as external coupling terminals has been provided ina lattice form on a lower surface (back surface) 3 b side of the packagesubstrate 3. It should be noted that the ball electrode 9 is, forexample, a solder ball.

When a detailed structure of the BGA 6 is explained, two semiconductorchips are mounted on the BGA 6 in a state of being stacked. In these twosemiconductor chips, the semiconductor chip arranged at a lower-stageside is a logic chip (a semiconductor chip or a microcomputer chipprovided with a microcomputer) 1, whereas the semiconductor chip on anupper-stage side that has been stacked over the logic chip 1 is a memorychip 2. It should be noted that the logic chip 1 and the memory chip 2are electrically coupled, and that the memory chip 2 of the upper-stageside is controlled by the logic chip 1 on the lower-stage side.Accordingly, the BGA 6 of the present embodiment can also be said to bean SIP (System In Package)-type semiconductor package.

It should be noted that flip-chip mounting of the logic chip 1 isperformed over the package substrate 3 via a plurality of copper (Cu)post bumps (copper pillar bumps, metal bumps, or metallic projectionelectrodes) 5, being projection electrodes. That is, as shown in FIG. 8which will be mentioned later, the logic chip 1 is arranged so that afront surface (first main surface) 1 a where elements have been formedand the plurality of copper post bumps 5 has been arranged faces anupper surface (front surface) 3 a of the package substrate 3, and thelogic chip 1 is mounted over the upper surface 3 a of the packagesubstrate 3.

Furthermore, a plurality of through electrodes 1 c is formed in thelogic chip 1. The through electrodes 1 c are formed penetrating asilicon base portion, and are electrically coupled to electrodes formedon the front and back surfaces of the chip.

As shown in FIG. 8, one ends of the through electrodes 1 c in the logicchip 1 of the BGA 6 are electrically coupled to one ends of wiringportions 1 g formed at an insulating layer 1 f of a surface layer on afront surface (an element formation surface or a lower surface) 1 a sideof the logic chip 1. Furthermore, the other ends of the wiring portions1 g are electrically coupled to pads 1 d formed on the front surface 1 aof the logic chip 1. Furthermore, the pads 1 d are electrically coupledto the copper post bumps 5. In addition, the other ends of the throughelectrodes 1 c are electrically coupled to bumps (electrode pads) 1 eprovided on a back surface (a second main surface or an upper surface) 1b side of an opposite side of the front surface 1 a of the logic chip 1.That is, the bumps 1 e provided on the back surface 1 b of the logicchip 1 are electrically coupled to the through electrodes 1 c, thewiring portions 1 g, the pads 1 d, and the copper post bumps 5 in thatorder from the back surface 1 b to the front surface 1 a of the logicchip 1.

Furthermore, as shown in FIG. 8, the bumps 1 e provided on the backsurface 1 b of the logic chip 1 and pads 2 d provided at a front surface2 a of the memory chip 2 are electrically coupled to one another, andthus the logic chip 1 and the memory chip 2 stacked over the backsurface 1 b of the logic chip 1 are electrically coupled to each other.

Specifically, as shown in FIG. 10, the bumps (electrode pads) 1 earranged in a matrix form are formed on the back surface 1 b of thelogic chip 1, whereas a plurality of bumps 2 e corresponding to thebumps 1 e is arranged over the front surface 2 a of the memory chip 2,and flip-chip coupling of the memory chip 2 and the logic chip 1 isperformed through the bumps 2 e coupled to the bumps 1 e.

In addition, the bumps 1 e are formed on the back surface 1 b of thelogic chip 1. Furthermore, there are formed recognition marks 1 h forrecognizing a chip position used for alignment, in a probe inspectionstep or a flip-chip mounting step among assembly steps of the BGA 6.

That is, the recognition marks 1 h are used to recognize them formed onthe back surface (upper surface) 1 b of the logic chip 1 and to performalignment of the logic chip 1, in the probe inspection step and theflip-chip mounting step in the assembly steps of the BGA 6.

In addition, the BGA 6 has a structure in which a power source, a GND,and a signal are supplied from the package substrate 3 to the memorychip 2 of the upper-stage side, via the logic chip 1.

It should be noted that as one example, a pitch of the copper post bumps5 is approximately not more than 100 μm, whereas a pitch of the bumps 1e of the opposite side is approximately 50 μm, and that in these ranges,there is satisfied a relation of an electrode pitch of the copper postbumps 5> an electrode pitch of the bumps 1 e. In addition, a pitch in aplanar view of the through electrodes 1 c arranged directly under therespective bumps 1 e is also approximately 50 μm similarly to theelectrode pitch of the bumps 1 e. Additionally, the package substrate 3and the logic chip 1 are electrically coupled to each other via thecopper post bumps 5.

It should be noted that, as shown in FIG. 8, on the upper surface 3 a ofthe package substrate 3, there are formed a plurality of lands (firstpad electrodes) 3 i and a solder resist film (insulating film) 3 k thatcovers an outer peripheral portion of the lands 3 i, and that the copperpost bumps 5 are electrically coupled to exposed portions of therespective lands 3 i via, for example, solders 7 which are conductivematerials.

Meanwhile, on the lower surface 3 b of the package substrate 3, thereare formed a plurality of lands 3 j and the solder resist film(insulating film) 3 k that covers an outer peripheral portion of thelands 3 j, and the ball electrodes 9 serving as the external couplingterminals are electrically coupled to exposed portions of the respectivelands 3 j.

In addition, the lands 3 i of the upper surface 3 a and the lands 3 j ofthe lower surface 3 b of the package substrate 3 are electricallycoupled via an internal wiring 3 g and a through-hole wiring 3 h.

In addition, as shown in FIG. 1, the logic chip 1 and the memory chip 2that have been stacked over the package substrate 3 are resin-sealed bya sealing body 4 including, for example, epoxy resin or the like.

Next, a method for manufacturing a semiconductor device of the presentembodiment will be explained.

FIG. 2 shows partial cross-sectional views each of which illustrates oneexample of a structure of the semiconductor device of FIG. 1 after fromelement formation to wiring formation of assembly thereof, FIG. 3 is apartial cross-sectional view illustrating one example of a structure ofthe semiconductor device of FIG. 1 after copper post bump formation ofthe assembly thereof, and FIG. 4 shows partial cross-sectional viewseach of which illustrates one example of a structure of thesemiconductor device of FIG. 1 after from wafer support attachment toback surface polishing of the assembly thereof. In addition, FIG. 5 is apartial cross-sectional view illustrating one example of a structure ofthe semiconductor device of FIG. 1 after back surface bump formation inthe assembly thereof, FIG. 6 shows partial cross-sectional views each ofwhich illustrates one example of a structure of the semiconductor deviceof FIG. 1 after from tape application to carrier removal of the assemblythereof, and FIG. 7 is a partial cross-sectional view showing oneexample of a structure of the semiconductor device of FIG. 1 afterdicing of the assembly thereof. Furthermore, FIG. 8 is a partialcross-sectional view illustrating one example of a structure of thesemiconductor device of FIG. 1 after flip-chip mounting of a lower-stagechip of the assembly thereof, FIG. 9 is a partial cross-sectional viewillustrating one example of a structure of the semiconductor device ofFIG. 1 at the time of alignment of the assembly thereof, and FIG. 10 isa partial cross-sectional view illustrating one example of a structureof the semiconductor device of FIG. 1 after flip-chip mounting of anupper-stage chip of the assembly thereof.

First, element formation shown in step S1 of FIG. 2 is performed. Here,elements is are formed at a front surface 8 a of a semiconductor wafer(hereinafter also simply referred to as a wafer) 8, which is asemiconductor substrate. Namely, elements 1 s such as transistors, areformed at a surface layer including an insulating layer 1 p andprotection film 1 q over a base substrate 1 r including silicon.

Next, through electrode formation of step S2 is performed. Here, first,a metal layer 1 m is formed over the front surface 8 a of the wafer 8,and after that, the through electrodes is electrically coupled to themetal layer 1 m are formed in the wafer 8. It should be noted that frontsurfaces of the respective through electrodes 1 c are covered with aninsulating film it of SiO₂ (also including TiN) or the like, whichprevents diffusion of the through electrodes 1 c. An inter-electrodepitch of the through electrodes 1 c is, for example, approximately 50 μmhere.

Next, wiring formation of step S3 is performed. Here, first, a metallayer 1 n is formed in the insulating layer 1 f over the front surface(a first surface) 8 a. Namely, the metal layer 1 n electrically coupledto the through electrodes 1 c is formed over the metal layer 1 m. Themetal layer 1 n includes a plurality of wiring layers, and an interlayerinsulating film is respectively formed between the respective wiringlayers.

Furthermore, the pads 1 d electrically coupled to the metal layer in areformed over the insulating layer 1 f. The pad 1 d is, for example, thepad formed of aluminum (Al) here.

Next, copper post bump formation of step S4 of FIG. 3 is performed.Here, the copper post bumps 5, being the plurality of projectionelectrodes electrically coupled to the metal layer in, are formed overthe metal layer 1 n. Namely, the copper post bumps 5, which are theprojection electrodes, are formed over the pads 1 d that have beenformed over the insulating layer 1 f and have been electrically coupledto the metal layer 1 n. Furthermore, the solders 7 are formed over therespective copper post bumps 5. It should be noted that although thepost bumps including copper (Cu) are exemplified and explained here, thepresent invention is not limited to this, and other metal post bumps maybe used.

In addition, the copper post bumps 5 are, for example, provided at apitch not more than 100 μm here. Since the number of terminals of thethrough electrodes 1 c required on an memory chip side is more than thenumber of copper post bumps coupled to a package substrate side, arelation of an electrode pitch of each of the copper post bumps 5> anelectrode pitch of each of the through electrodes 1 c, is satisfied.

Next, probe inspection is carried out. Namely, after the copper postbumps 5 are formed, probing is performed (a test probe, which is notshown, is applied) on the copper post bumps 5, and a first probeinspection, which is an electric test, is performed. This first probeinspection is the one to perform quality determination of the logic chip1 formed on the wafer 8, and is performed to a plurality of logic chips1 formed in a chip region of the wafer 8.

Next, wafer support attachment shown in step S5 of FIG. 4 is performed.Here, a front surface 8 a side of the wafer 8 is applied to a carrier 11through an adhesive 12. It should be noted that the carrier 11 is, forexample, a glass carrier including silica glass or the like. Inaddition, the adhesive 12 is, for example, an organic-based adhesive.However, the adhesive 12 is not limited to the organic-based adhesiveand an electrically conductive adhesive or the like may be used.

Next, back surface polishing (grinding or back grinding) shown in stepS6 of FIG. 4 is performed. Here, a back surface 8 b, on a side oppositeto the front surface 8 a of the wafer 8 is polished (ground), and thereis exposed a tip (a part) of each of the through electrodes 1 cpreviously formed in step S2. Polishing at this time is, for example,polishing, chemical etching or the like.

Next, back surface bump formation shown in step S7 of FIG. 5 isperformed. Here, first, an insulating film 1 u is formed around the tipsof the through electrodes 1 c exposed to the back surface 8 b of thewafer 8. This insulating film 1 u is, for example, an SiO₂ (alsoincluding TiN) film or the like. Furthermore, the bump 1 e is formed ateach of the tips of the through electrodes 1 c exposed to the backsurface 8 b side. The bump 1 e is, for example, formed by plating or thelike. In addition, the bump 1 e, for example, includes gold (Au) or thelike in many cases.

As a result, the bumps 1 e are formed on the back surface 8 b of thewafer 8. It should be noted that since the respective bumps 1 e areformed at the tips of the through electrodes 1 c exposed to the backsurface 8 b of the wafer 8, the electrode pitch of the bumps 1 e is thesame as the pitch of the through electrodes 1 c. Therefore, in the frontand back surfaces of the wafer 8, a relation of the electrode pitch ofthe respective copper post bumps 5> the electrode pitch of therespective bumps 1 e (through electrodes 1 c) is satisfied.

Next, a probe inspection is carried out. Here, there is carried out asecond probe inspection to inspect an electrical coupling state (aconductive state) of the copper post bumps 5 and the bumps 1 e. Itshould be noted that in the second probe inspection, the wafer 8 issupported in a state where the carrier 11 is applied to the wafer 8, andthat conduction between the electrodes of the respective bumps 1 e isconfirmed in this state.

That is, the second probe inspection is the one to perform qualitydetermination of the respective through electrodes 1 c formed in thewafer 8 (in the chip).

It should be noted that, in, the second probe inspection, there arerecognized the recognition marks 1 h formed on the back surface 1 b ofthe logic chip 1 shown in FIG. 8, and on the basis of this recognitionresult, a test needle of the probe is brought into contact with thebumps 1 e of the back surface 1 b of the logic chip 1, whereby the probeinspection I carried out.

After the above-described second probe inspection is completed, tapeapplication shown in step S8 of FIG. 6 is performed. Here, the backsurface 8 b side of the wafer 8 on which the above-described secondprobe inspection has been carried out is applied to a dicing tape 15.

Next, carrier removal shown in step S9 is performed. Here, the carrier11 applied to the front surface 8 a side through the adhesive 12 isremoved (eliminated) from the wafer 8, on which the above-describedsecond probe inspection has been finished and to which the dicing tape15 has been applied. Furthermore, etching is performed to remove theadhesive 12. At this time, the adhesive 12 is removed by etching andother foreign substances can also be removed, and cleaning of the copperpost bumps 5 and an element formation surface (front surface 8 a) can beperformed.

Next, dicing shown in step S10 of FIG. 7 is performed. Here, the wafer 8supported by the dicing tape 15 is cut off, and a plurality of goodsemiconductor chips (logic chips 1 here) are obtained.

Next, flip-chip mounting is performed.

Here, there is performed flip-chip mounting of the logic chip(lower-stage chip) 1 shown in step S11 in FIG. 8. First, the packagesubstrate (a wiring substrate or a multiple substrate) 3 is prepared. Itshould be noted that the lands 3 i coupled to the copper post bumps 5 ofthe logic chip 1 are formed on the upper surface 3 a of the packagesubstrate 3, whereas the lands 3 j electrically coupled to the lands 3 iare formed on the lower surface 3 b on a side opposite to the uppersurface 3 a of the package substrate 3.

In addition, the solder resist film 3 k is formed on a surface layer ofeach of the upper and lower surfaces of the package substrate 3, andparts of the respective lands 3 i and 3 j are exposed thereto.

After the package substrate 3 is prepared, the logic chip 1 determinedto be good by the second probe inspection is mounted over the uppersurface 3 a of the package substrate 3, and is heated and pressurized,whereby the package substrate 3 and the copper post bumps 5 areelectrically coupled via the solders 7 formed over the copper post bumps5. After that, an under filling 10, which is liquid-like sealing resin,is injected into a gap between the logic chip 1 and the packagesubstrate 3, and the gap is filled with the under filling 10. It shouldbe noted that, as to the injection and filling, the under filling 10,which is liquid-like sealing resin, is previously applied on the packagesubstrate 3, and by the mounting of the logic chip 1, there may beperformed, simultaneously, electrical coupling of the copper post bumps5 and the package substrate 3, and resin filling for the gap between thelogic chip 1 and the package substrate 3.

Next, a probe inspection is carried out. Here, there is carried out athird probe inspection to inspect an electrical coupling state of thelogic chip 1 and the package substrate 3. It should be noted that, inthe third probe inspection, there are recognized the recognition marks 1h formed on the back surface 1 b of the logic chip 1, and on the basisof this recognition result, a test needle of the probe is brought intocontact with the bumps 1 e of the back surface 1 b of the logic chip 1,whereby the conduction inspection is performed.

By the third probe inspection, it can be confirmed whether or notconduction of the logic chip 1 and the package substrate 3 is reliablysecured.

Next, there is performed stacking of the memory chip (upper-stage chip)2 shown in step S12 of FIG. 9.

First, alignment of the logic chip 1 and the memory chip 2, isperformed. Here, based on the recognition result of the recognitionmarks 1 h of the back surface 1 b of the logic chip 1 that has beenrecognized in the above-described third probe inspection, there isperformed alignment of the bumps 1 e of the back surface 1 b of thelogic chip 1 and the bumps 2 e of the front surface 2 a of the memorychip 2. After alignment is completed, flip-chip mounting of the memorychip 2 is then performed over the logic chip 1 as shown in FIG. 10.

Here, flip-chip mounting is performed by the following: alignment of thebumps 1 e of the logic chip 1 and the bumps 2 e of the memory chip 2 isperformed; and the memory chip 2 is mounted over the logic chip 1 sothat the back surface 1 b of the logic chip 1 and the front surface 2 aof the memory chip 2 face each other. After that, the gap between thelogic chip 1 and the memory chip 2 is filled with the under filling 10.

Next, in a resin sealing step, the logic chip 1, the memory chip 2, thecopper post bumps 5, the bumps 2 e and the like are covered with sealingresin and the sealing body 4 is formed, and furthermore, the ballelectrodes 9 serving as the external coupling terminals are mounted.After mounting, the package substrate 3 is separated into individualpieces, and assembly of the BGA 6 shown in FIG. 1 is completed.

Next, there will be explained an alignment method of a semiconductorwafer performed by the above-described probe inspection of the presentembodiment, and an alignment method of a semiconductor chip performed byflip-chip mounting. FIG. 11 is a conceptual diagram illustrating oneexample of a structure of a prober to which comparative examination hasbeen made, FIG. 12 shows a plan view and an enlarged plan viewillustrating a structure of a front surface side of a wafer mounted inthe prober of FIG. 11, FIG. 13 is a plan view illustrating a structureof a back surface side of the wafer mounted in the prober of FIG. 11,and FIG. 14 shows a plan view and a partial enlarged plan viewillustrating a structure of an A portion of FIG. 13. In addition, FIG.15 is a conceptual diagram illustrating an alignment method to whichcomparative examination has been made, and FIG. 16 shows a plan view andan enlarged partial plan view illustrating a recognition rangerecognized at the time of alignment shown in FIG. 15.

A prober 30 shown in FIG. 11 is the one to perform the probe inspectionof a wafer 31, in which the wafer 31 conveyed to an loader/unloader 30 dis ejected to be placed over a stage 30 a movable in X, Y, and Zdirections, and a plurality of probe needles 30 c provided at a testhead 30 b of the prober 30 is brought into contact with electrodes ofthe wafer 31, and a conduction inspection, an electrical characteristicinspection, and the like are carried out.

At this time, in the probe inspection, it is necessary to accuratelybring the probe needles 30 c into contact with test terminals (pads orbumps) provided with each chip, and to inspect characteristics.Therefore, the prober 30 that moves the wafer 31 in the chip unit needsto recognize one chip and to move with high accuracy. Accordingly, theprober 30 can move for one chip by recognizing a specified alignmentmark such as a unique pattern in the chip.

FIG. 12 shows the structure of a front surface 31 a side of the wafer 31in which a plurality of through electrodes 31 d have been formed, scribelines 31 c are formed on the front surface 31 a side other thanterminals of the through electrodes 31 d shown in the enlarged view, andthus division of the chip can be recognized. In addition, a uniquepattern including the above-described terminals or the like is repeatedin a chip region 31 e, the patterns of unique portions are recognized atthe time of alignment, and then alignment is performed. In addition tothat, alignment marks 31 f for alignment are also formed at corners ofthe chip region 31 e, and they are used for alignment of the wafer 31 atthe time of the above-described probe inspection.

Meanwhile, FIG. 13 shows the structure of the back surface 31 b side ofthe wafer 31, and only a plurality of bumps 31 g coupled to the throughelectrodes 31 d is seen. Accordingly, although the marks for alignmentare needed in the above-described probe inspection being performed bybringing the probe needles 30 c into contact with the bumps 31 g of theback surface 31 b side in a wafer state, only the bumps 31 g are seen onthe back surface 31 b side as mentioned above, and thus it is difficultto bring the probe needles 30 c into contact with the bumps 31 g in theabove-described probe inspection. For example, when recognition foralignment is performed on the back surface 31 b side of the wafer 31 inthe prober 30, shapes in a recognition range C and an imaging range Dimaged by a camera are the same as each other as shown in the A portionand a B portion of the enlarged view of FIG. 14, and thus there occurs aproblem that the shapes are determined to be similar patterns, and thatthe possibility of false recognition by the prober 30 becomes high.

In addition, this problem occurs also at the time of alignment of asemiconductor chip (for example, the memory chip 2 shown in FIG. 9) ofthe upper-stage side in chip stacking being performed. For example, whenflip-chip mounting of a chip 32 is performed on the wiring substrate 3shown in FIG. 15 and recognition for alignment of the above-describedupper-stage semiconductor chip stacked over the chip 32 is furtherperformed by recognizing the through electrodes 31 d by using a camera34, shapes in the recognition range C and the imaging range D of FIG. 14are the same as each other as with the time of the above-mentioned probeinspection, and thus there occurs a problem of having a high probabilityof false recognition.

It should be noted that, as to mounting of the chip 32 of a lower-stageside, since an inter-electrode pitch for flip-chip coupling (it is thepitch between the pads 1 d of FIG. 8, and is, for example, approximatelynot more than 100 μm) is much larger than a pitch (for example, around50 μm) between the through electrodes 31 d, it is possible to recognizemarks for alignment formed on the wiring substrate 3 and to performalignment.

However, since flip-chip mounting of the above-described semiconductorchip stacked on the upper-stage side is performed on through electrodes31 d arrayed at a narrow pitch of the lower-stage chip 32, the marks foralignment for securing positional accuracy is needed also at a backsurface of the chip 32.

It should be noted that as shown in FIG. 16, even if alignment marks 35including stipples are formed in the chip region 31 e, a shape of therecognition range C by the alignment marks 35 and a shape of the imagingrange D by the bumps 31 g are similar to each other in comparison withan array pattern of the bumps 31 g, and thus the possibility of falserecognition is high.

Next, a feature of the present embodiment will be explained.

FIG. 17 is a conceptual diagram illustrating one example of a state atthe time of alignment in a flip-chip step of the assembly of thesemiconductor device of FIG. 1, FIG. 18 is a conceptual diagramillustrating one example of a structure of the semiconductor device ofFIG. 1 after flip-chip mounting in the flip-chip step of the assemblythereof, FIG. 19 is a cross-sectional view illustrating one example of astructure at the time of alignment of FIG. 17, and FIG. 20 is across-sectional view illustrating one example of a structure after theflip-chip mounting shown in FIG. 18. In addition, FIG. 21 is a plan viewillustrating a structure of a front surface side of a wafer used in thepresent embodiment, FIG. 22 shows a plan view and a partial enlargedplan view illustrating a structure of an A portion of FIG. 21, and FIG.23 shows a plan view and a partial enlarged plan view illustrating astructure of the A portion of FIG. 21. Furthermore, FIG. 24 is a blockdiagram illustrating one example of a structure of a chip mountingmachine used in the flip-chip step of the assembly of the semiconductordevice of FIG. 1, FIG. 25 is a block diagram illustrating one example ofa structure of a prober apparatus used in an inspection step of theassembly of the semiconductor device of FIG. 1, and FIG. 26 is a partialcross-sectional view illustrating one example of a holding state of thewafer at the time of inspection in the prober apparatus of FIG. 25.

In the present embodiment, recognition marks 1 h for alignment areformed on the back surface 1 b of the logic chip 1 as shown in FIGS. 17and 18. Additionally, when flip-chip mounting of the memory chip 2 isperformed over the back surface 1 b of the logic chip 1, a shape in arecognition range including the recognition marks 1 h is recognized, andalignment of the memory chip 2 is performed.

As described above, the recognition marks 1 h for alignment are providedon the back surface 1 b of the logic chip 1, and thus false recognitioncan be more reduced than a case of recognizing a part of the throughelectrodes 1 c. Furthermore, as shown in FIGS. 19 and 20, when thememory chip 2 is mounted over the logic chip 1, alignment of the throughelectrodes 1 c of the logic chip 1 and the bumps 2 e of the memory chip2 can be performed with high accuracy. Here, FIG. 21 shows the backsurface 8 b side of the wafer 8 in which the recognition marks 1 h asshown in FIG. 22 have been formed, and in each chip region of the backsurface 8 b side, the bumps 1 e are provided, respectively, and therecognition marks 1 h are formed at chip corners as shown in FIG. 22.

It should be noted that the recognition marks 1 h shown in FIG. 22 arestipples by the bump 1 e coupled to each of the through electrodes 1 c,and that they look like what is called an L shape when viewed fromabove.

As a result, in a flip-chip coupling step, first, the recognition rangeC including the recognition mark 1 h over the back surface 1 b of thelogic chip 1 is imaged by the camera 14 shown in FIG. 19, and the shapeof the recognition range C shown in FIG. 22 is recognized.

Here, the shape of the recognition range C is different from any portionof the array shape of the bumps 1 e. Namely, on the back surface 1 bside of the logic chip 1, the shape of the recognition range C to beimaged by the camera 14 and to be recognized is not the same as thearray shape in the imaging range D in an array of the bumps 1 e.

It should be noted that “the shape is different” means that the shape ofthe recognition range. C including the recognition mark 1 h is differentfrom any portion of the array shape of the bumps 1 e of the back surface1 b of the logic chip 1. Alternatively, it means that, when the shape ofthe recognition range C including the recognition mark 1 h is overlappedwith a region where the bumps 1 e have been arrayed, the respectiveshapes do not coincide with each other (coincidence does not occur).

In an example shown in FIG. 22, the recognition mark 1 h includes anaggregate of a plurality of patterns 1 ha and furthermore, therecognition range C including the recognition mark 1 h has a firstregion 1 i where the patterns 1 ha have been arrayed, and a secondregion 1 j where the pattern 1 ha has not been arranged.

Meanwhile, the imaging range D has only a region (corresponding to thefirst region 1 i) where the bumps 1 e have been arranged, and does nothave a region corresponding to the above-described second region 1 j.

Accordingly, a shape of the recognition range C and an array shape ofthe imaging range D that have been formed over the chip are definitelydifferent from each other, and both are not similar patterns (similarshapes).

Accordingly, when the camera 14 images the back surface 1 b of the logicchip 1, false recognition of the array shape of the imaging range D asthe shape of the recognition range C to be recognized, can be reduced.

In addition, in a recognition unit of a chip mounting machine or thelike, when a mark of a predetermined location is recognized, anapproximate recognition position (a design value) is stored in thedevice, and operation to look for the mark is performed by setting acoordinate (X,Y) of the mark in many cases. However, when a similarpattern is formed around the coordinate, the recognition unit mayfalsely recognize this similar pattern as the mark. Accordingly, thesimilar pattern and a recognition pattern are preferably arranged as faras possible.

Here, FIG. 23 shows one solution of the problem (when a shape of analignment mark approximates to an array shape of a plurality ofelectrode pads, false recognition occurs at the time of recognition) ofthe invention in the present application. The A portion of FIG. 23 is acase where there is imaged a vicinity of a center of an array of thebumps 1 e, which is likely to be comparatively falsely recognized, andsince an array shape of the bumps 1 e of the imaging range D and anarray of the recognition marks 1 h of the recognition range Capproximate to each other, the possibility of false recognition is high.

Accordingly, positions of the bumps 1 e and the recognition marks 1 hcan be arranged away from each other by arrangement of the recognitionmarks 1 h at the corners of the back surface of the semiconductor chip,and as a result, false recognition can be prevented.

However, arrangement of the recognition marks 1 h at the positions awayfrom the bumps 1 e causes the increase of an area of the semiconductorchip.

Consequently, the shape of the recognition marks 1 h of the recognitionrange C is set to be a shape definitely different from the array shapeof the imaging range D like in the invention in the present applicationshown in FIG. 22, whereby the recognition marks 1 h can be arrangedclose to the bumps 1 e, and as a result, the area of the semiconductorchip can be reduced. Furthermore, there can be suppressed increase insize (increase in wafer size) of the semiconductor wafer where asemiconductor chip is formed.

Next, there will be explained a detailed method in flip-chip coupling ofthe memory chip 2 being performed over the logic chip 1 where therecognition marks 1 h shown in FIG. 22 have been formed.

First of all, there will be explained a chip mounting machine 13 shownin FIG. 24 used in flip-chip coupling. The chip mounting machine 13 has:the camera 14 that images the shape of the recognition range C includingthe recognition marks 1 h of the logic chip 1 shown in FIG. 22; arecognition unit 16 that stores image data imaged by the camera 14 andthat processes the above-described image data; and a chip mounting unit17 that positions and mounts the memory chip 2 of the upper-stage sideon the basis of the above-described image data which the recognitionunit 16 has processed.

At the time of flip-chip coupling, first, the recognition range Cincluding the recognition marks 1 h on the back surface 1 b of the logicchip 1 of FIG. 22 is imaged by the camera 14 of the chip mountingmachine 13, and the shape of the recognition range C is recognized. Atthis time, a comparison is made between each other are image data of theshape of the recognition range C previously stored in the recognitionunit 16, and image data of the shape of the recognition range C newlyimaged by the camera 14. In that case, as to the shape of therecognition range C and the array shape of the imaging range D of thebumps 1 e, the shape of the recognition range C differs from any portionof the above-described array shape, and thus the array shape of theimaging range D is not falsely recognized as the shape of therecognition range C to be recognized, and the shape of the recognitionrange C can be reliably recognized by the recognition unit 16.

Next, alignment of the bumps 1 e of the logic chip 1 and the bumps 2 eof the memory chip 2, which are projection electrodes, is performed bythe chip mounting unit 17 on the basis of a result of having recognizedthe shape of the recognition range C, as shown in FIG. 9.

Furthermore, after the above-described alignment, the memory chip 2 ismounted over the logic chip 1 by the chip mounting unit 17, and thebumps 1 e of the logic chip 1 and the bumps 2 e of the memory chip 2 areelectrically coupled to one another. As a result of this, flip-chipcoupling is completed.

As described above, the recognition marks 1 h that form the shapedifferent from the array shape of the bumps 1 e are formed on the backsurface 1 b of the logic chip 1, whereby the recognition marks 1 h inthe shape of the recognition range C can be reliably recognized, andalignment of the bumps 1 e of the logic chip 1 and the bumps 2 e of thememory chip 2 can be performed with high accuracy.

As a result of it, reliability of flip-chip coupling can be enhanced,and assemblability of the semiconductor device (BGA 6) can be improved.

Next, there will be explained a detailed method that performs alignmentof the logic chip 1 (semiconductor wafer 8) where the recognition marks1 h shown in FIG. 22 have been formed and probe needles at the time ofthe probe inspection (the second probe inspection or the third probeinspection) in an assembly step of the BGA 6 of the present embodiment.

First of all, there will be explained a prober apparatus shown in FIG.25 used in the above-described probe inspection. The prober apparatus 18has: a camera 19 that images the shape of the recognition range Cincluding the recognition marks 1 h; a recognition unit 20 that storesimage data imaged by the camera 19 and that processes theabove-described image data; a plurality of probe needles 21 that makescontact with a semiconductor chip based on the above-described imagedata that the recognition unit 20 has processed; and a measurement unit22 that measures electrical characteristics of the above-describedsemiconductor chip through the probe needles 21.

At the time of the probe inspection, first, the recognition range Cincluding the recognition marks 1 h on the back surface 1 b of the logicchip 1 of FIG. 22 is imaged by the camera 19 of the prober apparatus 18,and the shape of the recognition range C is recognized. At this time,compared with each other are image data of the shape of the recognitionrange C previously stored in the recognition unit 20, and image data ofthe shape of the recognition range C newly imaged by the camera 19. Inthat case, since, as to the shape of the recognition range C and thearray shape of the imaging range D of the bumps 1 e, the shape of therecognition range C differs from any portion of the above-describedarray shape, the array shape of the imaging range D is not falselyrecognized as the shape of the recognition range C to be recognized, andthe shape of the recognition range C can be reliably recognized by therecognition unit 20.

After that, on the basis of a result of having recognized the shape ofthe recognition range C, there is performed alignment of the bumps 1 eof the logic chip 1 shown in FIG. 9 (or the bumps 1 e of the backsurface 8 b of the wafer 8 of FIG. 5), and the probe needles 21 of FIG.25.

After the above-described alignment, the probe needles 21 are broughtinto contact with the respective the bumps 1 e of the logic chip 1, andelectrical characteristics of the logic chip 1 are further measured bythe measurement unit 22.

As described above, the recognition marks 1 h that form the shapedifferent from the array shape of the bumps 1 e are formed on the backsurface 1 b of the logic chip 1, whereby the recognition marks 1 h inthe shape of the recognition range C can be reliably recognized, andalignment of the bumps 1 e of the logic chip 1 and the probe needles 21of the prober apparatus 18 can be performed with high accuracy.

As a result, reliability of the inspection in the probe inspection canbe enhanced, and assemblability of the semiconductor device (BGA 6) canbe improved.

It should be noted that, when the second probe inspection is performedafter the bumps 1 e are formed in a back surface bump formation step ofstep S7 shown in FIG. 5, the probe inspection is performed in a statewhere the wafer 8 is applied to the carrier 11. The probe inspection inthis wafer state is, as shown in FIG. 26, performed in a state ofholding the wafer 8 over a stage 23 of the prober apparatus 18 via thecarrier 11.

When the probe inspection is carried out in this wafer state, the wafer8 is diced as shown in FIG. 7 after the probe inspection, the logic chip1 determined to be good by the above-described probe inspection (thesecond probe inspection) is obtained and after that, the good logic chip1 is mounted on the package substrate 3 as shown in FIG. 8.

It should be noted that the above-described second and third probeinspections need not be necessarily carried out in the assembly of theBGA 6 of the present embodiment. In addition, any one of theabove-described second and third probe inspections may be carried out,or both of them may be carried out.

In addition, also in the flip-chip coupling of the memory chip 2 of theupper-stage side shown in FIG. 9, alignment performed by imaging therecognition marks 1 h need snot be necessarily carried out. However, inthat case, alignment with the probe needles 21 performed by imaging therecognition marks 1 h is performed in at least any one of theabove-described second and third probe inspections.

In addition, the shape of the recognition range including therecognition marks 1 h imaged in the above-described first and secondprobe inspections may just be in common with the shape of therecognition range C including the recognition marks 1 h imaged in theflip-chip coupling of the memory chip 2 of the upper-stage side shown inFIG. 9. Namely, the recognition marks 1 h imaged for alignment in theprobe inspection and flip-chip coupling may just be used in common.

As a result, there can be avoided the formation of different recognitionmarks 1 h on the back surface of the chip for every step, and a regionin the semiconductor chip can be efficiently used.

Next, a formation method of the recognition marks 1 h of the presentembodiment will be explained.

FIG. 27 shows cross-sectional views illustrating one example of arecognition mark formation step in a semiconductor chip incorporated inthe semiconductor device of FIG. 1, FIG. 28 shows cross-sectional viewsillustrating one example of the recognition mark formation step in thesemiconductor chip incorporated in the semiconductor device of FIG. 1,and FIG. 29 shows cross-sectional views illustrating a firstmodification of the recognition mark formation step in the semiconductorchip incorporated in the semiconductor device of FIG. 1.

Furthermore, FIG. 30 is a conceptual diagram illustrating one example ofpitches and a size of the patterns by the through electrodes of FIG. 22,and FIG. 31 is a plan view illustrating one example of a structure of aback surface side of a logic chip incorporated in the semiconductordevice of FIG. 1.

First of all, a case will be explained where a recognition mark isformed in a step other than a through electrode formation step. As shownin step S21 of FIG. 27, first, elements is are formed at the frontsurface 8 a of the wafer 8. Namely, the elements is such as transistors,are formed at a surface layer including the insulating layer 1 p and theprotection film 1 q over the base substrate 1 r including silicon.

Next, through electrode formation is performed. Here, the metal layer 1m is formed over the front surface 8 a of the wafer 8, and after that,the through electrodes 1 c electrically coupled to the metal layer 1 mare formed in the wafer 8. It should be noted that front surfaces of therespective through electrodes 1 c are covered with the insulating film 1t of SiO₂ (also including TiN) or the like, which prevents diffusion ofthe through electrodes 1 c.

Next, after the copper post bumps 5 are formed at the pads 1 d, thecarrier 11 is applied to the wafer 8 via the adhesive 12. Furthermore,back surface polishing shown in step S22 is performed. Namely, thepolishing of the back surface 8 b of the wafer 8 held by the carrier 11projects tips of the through electrodes 1 c.

Next, back surface bump formation shown in step S23 of FIG. 28 isperformed. Here, the bump 1 e is formed at the each tip of therespective through electrodes 1 c.

Next, mark formation shown in step S24 is performed. For example,recognition marks 1 k are formed, by plating or the like, on the backsurface 8 b of the wafer 8.

As described above, the recognition marks 1 k are formed in the stepother than the through electrode formation step, and thus it is possibleto form a shape of the recognition marks 1 k completely different fromthe array shape of the through electrodes 1 c. Namely, there can beformed the recognition marks 1 k having completely changed size, form,pitch or the like differently from the recognition marks 1 h.

It should be noted that, as shown in FIG. 30, in the through electrodes1 c arrayed in a matrix form, the following are defined by JEDEC (JointElectron Device Engineering Council standards): X=50 μm; Y=40 μm, X andY being pitches between adjacent electrodes; and φ=20 μm, φ being adiameter of the electrode.

Accordingly, when the recognition marks 1 k are formed in the step otherthan the through electrode formation step, the pitches and the diameterare not limited to the above numerical values, and the recognition mark1 k may be formed by changing pitch, size, form or the like, or may beformed in the same pitch, diameter, and form as the above.

Meanwhile, the first modification shown in FIG. 29 illustrates a casewhere the recognition marks 1 h are formed simultaneously in the throughelectrode formation step.

First of all, elements is are formed at the front surface 8 a of thewafer 8. Namely, the elements is such as transistors, are formed at thesurface layer including the insulating layer 1 p and the protection film1 q over the base substrate 1 r including silicon.

Next, as shown in step S31, a plurality of through electrodes 1 v forthe recognition marks 1 h are formed together with the throughelectrodes 1 c in the through electrode formation step. First, the metallayer 1 m is formed over the front surface 8 a of the wafer 8, and afterthat, the through electrodes 1 c and 1 v electrically coupled to themetal layer 1 m are formed in the wafer 8. It should be noted that frontsurfaces of the respective through electrodes 1 c and 1 v are coveredwith the insulating film it of SiO₂ (also including TiN) or the like,which prevents diffusion of the through electrodes 1 c and 1 v.

Furthermore, after the copper post bumps 5 are formed on the pads 1 d,the carrier 11 is applied to the wafer 8 through the adhesive 12. Afterthat, back surface polishing shown in step S32 is performed. Namely, thepolishing of the back surface 8 b of the wafer 8 held by the carrier 11projects respective tips of the through electrodes 1 c and 1 v.

Next, mark formation (back surface bump formation) shown in step S33 isperformed. Here, the bump 1 e is formed at the respective tips of thethrough electrodes 1 c projecting to the back surface 8 b of the wafer8, and the recognition mark 1 h is formed at the respective tips of thethrough electrodes 1 v. It should be noted that the bumps 1 e and therecognition marks 1 h are, for example, formed by plating or the like.

It should be noted that when the recognition mark 1 h is formedsimultaneously in the through electrode formation step, the recognitionmarks 1 h are represented as an aggregate of stipples (patterns 1 ha) ora single stipple.

Since the recognition marks 1 h are formed simultaneously in the throughelectrode formation step as described above, and thus the throughelectrodes 1 v for the recognition marks can be formed simultaneouslywith the through electrode 1 c by using a sheet of mask, the pluralityof recognition marks 1 h can be formed with high accuracy.

Furthermore, the step of forming the recognition marks 1 h can beomitted, and as a result, the recognition marks 1 h can be efficientlyformed.

In addition, also in the case where the recognition marks 1 h are formedsimultaneously in the through electrode formation step, it is alsopossible to change pitches and sizes of the adjacent through electrodes1 v, and to change a shape of the through electrode 1 v differently fromthat of the through electrode 1 c. For example, only the above-describedpitch X may be changed, and only the above-described pitch Y may bechanged, or both of the above-described pitches X and Y may be changed.

However, the through electrodes 1 v may be formed to have the samepitch, diameter, and shape as the through electrodes 1 c.

Next, using FIG. 31, there will be explained formation positions of therecognition marks 1 h in a case where a shape of the back surface 1 b ofthe logic chip 1 is substantially square.

The through electrodes 1 c are arranged in a matrix form in a center ofthe back surface 1 b of the logic chip 1. Accordingly, it is necessaryto secure a cell region around the through electrodes 1 c. Consequently,the recognition marks 1 h are, as shown in FIG. 31, preferably formed atpositions away from a region of the back surface 1 b where the throughelectrodes 1 c have been arranged. For example, the positions are endregions such as corners of the back surface 1 b.

As a result, the cell region can be sufficiently secured. Furthermore,the recognition marks 1 h are formed at the positions (ends of the backsurface 1 b) away from the region where the through electrodes 1 c ofthe back surface 1 b have been arranged, and thus a recognition rate ofthe recognition marks 1 h can be increased. Namely, the recognitionmarks 1 h are formed at the position sufficiently away from the bumps 1e coupled to the through electrodes 1 c, whereby the recognition marks 1h are easily recognized in being imaged by the cameras 14 and 19, andthe recognition rate of the recognition mark 1 h can be increased.

However, when the recognition marks 1 h are formed at a position nearthe region where the bumps 1 e (through electrodes 1 c) have beenarranged as shown in the logic chip 1 of FIG. 22, a distance of the bump1 e and the recognition mark 1 h is short, and thus chip mountingaccuracy in the case of performing flip-chip coupling can be increased.

Accordingly, although the recognition marks 1 h are preferably formed atthe position away from the bumps 1 e (through electrodes 1 c) in orderto increase the recognition rate of the recognition marks 1 h, when thechip mounting accuracy at the time of flip-chip coupling needs to beincreased, the recognition marks 1 h may be formed at the position nearthe bumps 1 e (through electrodes 1 c).

Next, other modifications will be explained.

FIG. 32 shows a plan view and an enlarged partial plan view illustratingshapes of a recognition range of a second modification, FIG. 33 shows aplan view and an enlarged partial plan view illustrating shapes of arecognition range of a third modification, FIG. 34 shows a plan view andan enlarged partial plan view illustrating shapes of recognition rangeof a fourth modification, FIG. 35 shows a plan view and an enlargedpartial plan view illustrating shapes of a recognition range of a fifthmodification, and FIG. 36 shows a plan view and an enlarged partial planview illustrating shapes of a recognition range of a sixth modification.In addition, FIG. 37 shows a plan view and an enlarged partial plan viewillustrating shapes of a recognition range of a seventh modification,FIG. 38 is an enlarged plan view illustrating a shape of a recognitionrange of an eighth modification, FIG. 39 is an enlarged plan viewillustrating a shape of a recognition range of a ninth modification, andFIG. 40 is an enlarged plan view illustrating a shape of a recognitionrange of a tenth modification. Furthermore, FIG. 41 is a cross-sectionalview illustrating a structure of a semiconductor device of an eleventhmodification of the embodiment, FIG. 42 is an enlarged partialcross-sectional view illustrating structure of a semiconductor device ofa twelfth modification of the embodiment, FIG. 43 is a cross-sectionalview illustrating a structure of a semiconductor device of a thirteenthmodification of the embodiment, and FIG. 44 is cross-sectional viewillustrating a structure of a semiconductor device of a fourteenthmodification of the embodiment.

Note that, although in the modifications of FIGS. 32 to 37, forconvenience, there will be taken up and explained a case where a shapeof the back surface of the chip is a rectangle, and where therecognition marks 1 h are formed at the positions near the region wherethe bumps 1 e have been arranged, it is needless to say that the shapeof the back surface of the chip, and an arrangement relationship of therecognition marks 1 h and the bumps 1 e may be an almost square shapesimilarly to the logic chip 1 shown in FIG. 31.

The second modification shown in FIG. 32 illustrates a modification ofthe recognition marks 1 h, the recognition mark 1 h includes anaggregate of the patterns 1 ha, and has a + shape in a planar view, andthe recognition range C including the recognition mark 1 h has, at fourpoints (four corners), the second region 1 j where the patterns 1 ha arenot arranged.

Meanwhile, since the imaging range D does not have a regioncorresponding to the above-described second region 1 j, a shape in therecognition range C and an array shape in the imaging range D aredefinitely different from each other, and both are not similar patterns(similar shapes).

As a result, when the camera 14 of FIG. 24 and the camera 19 of FIG. 25image the back surface 1 b of the logic chip 1, false recognition of thearray shape of the imaging range D as the shape of the recognition rangeC to be recognized, can be reduced.

In addition, the third modification shown in FIG. 33 also illustrates amodification of the recognition mark 1 h, the recognition mark 1 hincludes a single first pattern 1 hb, and represents a circle in theplanar view. Furthermore, although respective areas of the bumps 1 e areequal to each other, an area of the first pattern 1 hb and therespective areas of the bumps 1 e are different from each other, and thearea of the first pattern 1 hb is much larger than the respective areasof the bumps 1 e.

It should be noted that, also in the third modification, the recognitionrange C including the recognition mark 1 h has the second region 1 jwhere the first pattern 1 hb is not arranged.

Meanwhile, since the imaging range D does not have the regioncorresponding to the above-described second region 1 j, a shape in therecognition range C and an array shape in the imaging range D aredefinitely different from each other, and both are not similar patterns(similar shapes).

As a result, when the camera 14 of FIG. 24 and the camera 19 of FIG. 25image the back surface 1 b of the logic chip 1, false recognition of thearray shape of the imaging range D as the shape of the recognition rangeC to be recognized, can be reduced.

In addition, the area of the first pattern 1 hb is much larger than thearea of each of the bumps 1 e, and sizes of the first pattern 1 hb andthe bump 1 e are obviously different from each other, and thus arecognition rate of the recognition range C including the recognitionmark 1 h can be further increased.

In addition, the fourth modification shown in FIG. 34 also illustrates amodification of the recognition mark 1 h, and the recognition mark 1 hhas the first pattern 1 hb, a second pattern 1 hc, a third pattern 1 hd,and a fourth pattern 1 he. Here, when viewed on the basis of the firstpattern 1 hb, the second pattern 1 hc is arranged along a firstdirection 1 w, and the third pattern 1 hd is arranged along a seconddirection 1 x perpendicular to the first direction 1 w. Furthermore, thefourth pattern 1 he is arranged along the first direction 1 w on thebasis of the third pattern 1 hd. It should be noted that the firstpattern 1 hb, the second pattern 1 hc, the third pattern 1 hd, and thefourth pattern the are respectively circular in the planar view, andthat areas of the respective patterns are equal to each other, andfurthermore, the respective areas of the respective patterns aredifferent from the respective areas of the bumps 1 e.

Namely, each of the circular areas (sizes) of the first pattern 1 hb,the second pattern 1 hc, the third pattern 1 hd, and the fourth pattern1 he is obviously different from the area (size) of each of the bumps 1e. That is, each of the areas of the respective patterns is obviouslylarger than the area (size) of each of the bumps 1 e.

In addition, a distance P1 between pitches of the first pattern 1 hb andthe second pattern 1 hc is larger than a distance P2 between the pitchesof the respective bumps 1 e, and a relation of P1>P2 is satisfied.Furthermore, a distance P3 between pitches of the first pattern 1 hb andthe third pattern 1 hd is larger than the distance P2 between thepitches of the respective bumps 1 e, and a relation of P3>P2 issatisfied.

Namely, since in the fourth modification, sizes of the individualpattern and the each bump 1 e are completely different from one another,and arrangement pitches with the adjacent patterns (bumps 1 e) thereofare also definitely different from one another, a shape of therecognition range C and the array shape of the imaging range D arecertainly different from each other, and both are further obviouslydifferent shapes in the fourth modification.

Accordingly, when the camera of FIG. 24 and the camera of FIG. 25 imagethe back surface 1 b of the logic chip 1, false recognition of the arrayshape of the imaging range D as the shape of the recognition range C tobe recognized, can be further reliably reduced.

In addition, the fifth modification shown in FIG. 35 also illustrates amodification of the recognition mark 1 h, and the recognition mark 1 hincludes the single first pattern 1 hb, and is circular in the planarview. Furthermore, although respective areas of the bumps 1 e are equalto each other, an area of the first pattern 1 hb and the area of each ofthe bumps 1 e are different from each other, and the area of the firstpattern 1 hb is much larger than the area of each of the bumps 1 e.

Accordingly, a shape in the recognition range C and an array shape inthe imaging range D are certainly different from each other, and bothare not similar patterns (similar shapes).

As a result, when the camera 14 of FIG. 24 and the camera 19 of FIG. 25image the back surface 1 b of the logic chip 1, false recognition of thearray shape of the imaging range D as the shape in the recognition rangeC to be recognized, can be reduced.

Furthermore, an area of the recognition range C of the fifthmodification of FIG. 35 corresponds to an area of one first pattern 1hb, and is much smaller as compared with the recognition range C of FIG.22.

Accordingly, an area of the cell region can be largely secured bynarrowing the recognition range C.

In addition, the sixth modification shown in FIG. 36 also illustrates amodification of the recognition mark 1 h, and the recognition mark 1 hincludes a plurality of first patterns 1 hb, and has an L shape in theplanar view. Furthermore, although respective areas of the firstpatterns 1 hb are equal to each other, they are different from therespective areas of the bumps 1 e, and the area of the first pattern 1hb is much smaller than the area of each of the bumps 1 e.

In addition, an arrangement pitch of the first patterns 1 hb and anarrangement pitch of the bumps 1 e are also different from each other,and the arrangement pitch of the first patterns 1 hb is much smallerthan that of the bumps 1 e.

It should be noted that, also in the sixth modified embodiment, therecognition range C including the recognition mark 1 h has the secondregion 1 j where the first pattern 1 hb is not arranged.

Accordingly, a shape in the recognition range C and an array shape inthe imaging range D are definitely different from each other, and bothare not similar patterns (similar shapes).

As a result, when the camera 14 of FIG. 24 and the camera 19 of FIG. 25image the back surface 1 b of the logic chip 1, false recognition of thearray shape of the imaging range D as the shape in the recognition rangeC to be recognized, can be reduced.

Furthermore, also in the sixth modified embodiment, an area of the cellregion can be largely secured since the recognition range C is narrow.

In addition, the seventh modification shown in FIG. 37 also illustratesa modification of the recognition mark 1 h, the recognition mark 1 hincludes the first patterns 1 hb and second patterns 1 hc, and the firstpattern 1 hb and the second pattern 1 hc are alternately lined up in astaggered arrangement in the first direction 1 w and the seconddirection 1 x.

It should be noted that areas of the first pattern 1 hb and the secondpattern 1 hc are equal to each other, and that the area of each of thefirst pattern 1 hb and the second pattern 1 hc is also equal to the areaof each of the bumps 1 e.

However, the first patterns 1 hb and second patterns 1 hc arealternately lined up in the staggered arrangement, and an arrangementpitch of the first pattern fhb and the second pattern 1 hc isapproximately twice as large as the arrangement pitch of the bumps 1 e.

Accordingly, since both arrangement pitches are completely differentfrom each other, a shape in the recognition range C and an array shapein the imaging range D are certainly different from each other, and bothare not similar patterns (similar shapes).

As a result, when the camera 14 of FIG. 24 and the camera 19 of FIG. 25image the back surface 1 b of the logic chip 1, false recognition of thearray shape of the imaging range D as the shape in the recognition rangeC to be recognized, can be reduced.

Next, the modifications shown in FIGS. 38 to 40 show the modificationsof a shape of one pattern 1 ha of the recognition marks 1 h in theplanar view. First, the eighth modification shown in FIG. 38 is a casewhere the shape of one pattern 1 ha of the recognition marks 1 h is anoctagon in the planar view. In addition, the ninth modification shown inFIG. 39 is a case where the shape of one pattern 1 ha of the recognitionmarks 1 h is the + shape in the planar view. Furthermore, the tenthmodification shown in FIG. 40 is a case where the shape of one pattern 1ha of the recognition marks 1 h is a − shape in the planar view.

As described above, even if the shape of one pattern 1 ha of therecognition marks 1 h is set to be the shapes of the modifications shownin FIGS. 38 to 40, there can be obtained a similar effect to the case ofbeing the circle shown in FIG. 22.

Next, the modifications shown in FIGS. 41 to 44 are the modificationsregarding the structure of the semiconductor device.

First, the eleventh modification shown in FIG. 41 illustrates a BGA(semiconductor device) 25 in which the logic chip 1 and the memory chip2 stacked thereover are not resin-sealed but are sealed by a case 24.Also in this BGA 25, in a flip-chip coupling step and a probe inspectionstep in the assembly thereof, the recognition range C including therecognition mark 1 h as shown in FIG. 22 is recognized, and thusalignment of narrow-pitch electrodes at the time of flip-chip couplingof the memory chip 2 to be stacked and alignment of the probe needles 21(refer to FIG. 25) with the narrow-pitch electrodes at the time of theprobe inspection can be performed with high accuracy. As a result,assemblability of the BGA 25 can be enhanced.

In addition, a stacked structure of the twelfth modification of FIG. 42shows a semiconductor device in which a plurality of memory chips 2 hasbeen stacked over the logic chip 1. Namely, the semiconductor device hasthe structure in which the logic chip 1 has been mounted over thepackage substrate 3 through the copper post bumps 5, and in which thememory chips 2 have been stacked over the logic chip 1.

At this time, the through electrodes 1 c and 2 c are formed in the logicchip 1 and each of the memory chips 2 stacked thereover. The throughelectrodes 1 c and 2 c are formed penetrating a silicon base portion,and are via wirings that electrically couple electrodes of the front andback surfaces of the chip. Namely, the through electrodes 1 c and 2 care the electrodes formed by boring through-holes in the chip in a waferstate, and embedding conductive materials therein, and they areeffective for stacking a number of semiconductor chips in a state wherea narrow pad pitch is maintained.

Consequently, the through electrode 1 c in the logic chip 1 electricallycouples the copper post bumps 5 coupled to the pads 1 d of the frontsurface 1 a, and the bumps 1 e provided on the back surface 1 b side ona side opposite thereto, via the wiring portions 1 g formed at theinsulating layer 1 f of a surface layer.

Meanwhile, the through electrodes 2 c in the memory chip 2 electricallycouples the pads 2 d provided on the front surface 2 a, and the bumps 2e provided on a back surface 2 b side on a side opposite thereto, viawiring portions 2 g similarly formed at an insulating layer 2 f of asurface layer.

It should be noted that, in a stacked layer of the logic chip 1 and thememory chips 2 (second semiconductor chips or third semiconductor chips)of the upper-stage side of the logic chip 1, the bumps 1 e directlycoupled to the through electrodes 1 c of the logic chip 1, and the pads2 d of the front surface 2 a side of the memory chip 2 are electricallycoupled to one another. Furthermore, the stacked structure is thestructure in which the bumps 2 e of an upper surface side that aredirectly coupled to the through electrodes 2 c of a second-stage memorychip 2, and the pads 2 d of a lower surface side of a third-stage memorychip 2 have been electrically coupled to one another. The second-stagememory chip 2 and the third-stage memory chip 2 are the same chips.

For example, when the third-stage memory chip 2 is stacked over thesecond-stage memory chip 2, alignment is performed by recognizingrecognition marks 2 h formed on the back surface 2 b of the second-stagememory chip 2, and thus alignment can be performed with high accuracybetween the second-stage memory chip 2 and the third-stage memory chip2.

Here, as one example of a semiconductor device in which the structureshown in FIG. 42 has been resin-sealed, there is illustrated a BGA 26 ofthe thirteenth modification of FIG. 43.

In addition, as one example of a semiconductor device in which thestructure shown in FIG. 42 has been sealed by the case 24, there isillustrated a BGA 27 of the fourteenth modification of FIG. 44.

Also in the BGA 26 shown in FIG. 43 and the BGA 27 shown in FIG. 44, inflip-chip coupling steps and probe inspection steps in the assemblythereof, the recognition range C including the recognition mark 1 h asshown in FIG. 22 is recognized, and thus alignment of narrow-pitchelectrodes at the time of flip-chip coupling of the memory chips 2 to bestacked can be performed with high accuracy. Furthermore, alignment ofthe probe needles 21 (refer to FIG. 25) with the narrow-pitch electrodesat the time of a probe inspection can be performed with high accuracy.As a result, assemblability of the BGAs 26 and 27 can be improved.

Hereinbefore, although the invention made by the inventor has beenspecifically explained based on the embodiment, it is needless to saythat the present invention is not limited to the above-describedembodiment, and that various modifications can be made without departingfrom the gist of the invention.

For example, in the above-described embodiment and modifications, a BGtape other than a carrier or the like may be used as a support memberthat supports a wafer in an assembly step.

In addition, although the cases where the semiconductor device is theBGA have been taken up and explained in the above-described embodimentand modifications, the semiconductor device is not limited to the BGA,but may be, for example, an LGA (Land Grid Array) and the like, as longas the semiconductor has a structure in which a plurality ofsemiconductor chips is stacked over a wiring substrate.

In addition, the following embodiments may be included.

APPENDIX Paragraph 1

A method for manufacturing a semiconductor device, including the stepsof:

(a) preparing a first semiconductor chip that has a first main surfaceand a second main surface on a side opposite to the first main surface,and a second semiconductor chip that has a first main surface, and asecond main surface on a side opposite to the first main surface; and

(b) mounting the second semiconductor chip over the first semiconductorchip so that the second main surface of the first semiconductor chip andthe first main surface of the second semiconductor chip face each other,in which

a plurality of electrode pads arranged in a matrix form and arecognition mark are arranged over the second main surface of the firstsemiconductor chip,

a plurality of projection electrodes corresponding to the electrode padsof the first semiconductor chip is arranged over the first main surfaceof the second semiconductor chip,

the (b) step including the steps of:

(b1) imaging a recognition range including the recognition mark over thesecond main surface of the first semiconductor chip, and recognizing ashape of the recognition range;

(b2) performing alignment of the electrode pads of the firstsemiconductor chip and the projection electrodes of the secondsemiconductor chip based on a result of having recognized the shape ofthe recognition range; and

(b3) mounting the second semiconductor chip over the first semiconductorchip, and electrically coupling the electrode pads of the firstsemiconductor chip and the projection electrodes of the secondsemiconductor chip, and in which

the shape of the recognition range is different from any portion of anarray shape of the electrode pads.

Paragraph 2

The method for manufacturing the semiconductor device according toparagraph 1, in which the first semiconductor chip is a logic chipprovided with a microcomputer, and the second semiconductor chip is amemory chip.

Paragraph 3

The method for manufacturing the semiconductor device according toparagraph 2, in which a third semiconductor chip is mounted over thesecond semiconductor chip.

Paragraph 4

The method for manufacturing the semiconductor device according toparagraph 3, in which the second semiconductor chip and the thirdsemiconductor chip are the same chips.

Paragraph 5

The method for manufacturing the semiconductor device according toparagraph 4, in which the third semiconductor chip is a memory chip.

Paragraph 6

The method for manufacturing the semiconductor device according toparagraph 1, including the step of, after the (b) step, sealing thefirst semiconductor chip, the second semiconductor chip, and theprojection electrodes.

1-20. (canceled)
 21. A method for manufacturing a semiconductor device,comprising the steps of: (a) preparing a first semiconductor chip thathas a first main surface and a second main surface on a side opposite tothe first main surface, and a second semiconductor chip that has a firstmain surface, and a second main surface on a side opposite to the firstmain surface; and (b) mounting the second semiconductor chip over thefirst semiconductor chip so that the second main surface of the firstsemiconductor chip and the first main surface of the secondsemiconductor chip face each other, wherein a plurality of electrodepads arranged in a matrix form and a recognition mark are arranged overthe second main surface of the first semiconductor chip, wherein aplurality of projection electrodes corresponding to the electrode padsof the first semiconductor chip is arranged over the first main surfaceof the second semiconductor chip.